Bicycle



Patented May 9, |899.

J. J. HENTZ.

BICYCLE.

(Application Sled Nov. 3, 1897.)

(NS muni.)

, the inner face of a sprocket-wheel.

IINTTED STATES PATENT GFEICE.

JOHN J. HENTZ, OF BALTIMRE, MARYLAND.

BICYCLE.

SPECIFICATION forming part of Letters Patent No. 624,651, dated May 9, 1899.

Application filed November 3, 1897. Serial No. 657,306. (No model.)

To all whom it may concer-71,:

Be it known that I, JOHN J. HENTZ, of Baltimore city, in the State of Maryland,'have invented a new and useful Improvement in Bicycles,which improvement is fully set forth in the following specification and accompanying drawings.

The object of my invention is to furnish a device by which to connect or disconnect the sprocket-Wheels with the shaft on which they are placed, so that the motion of the shaft may be communicated to the one or the other of the sprocket-wheels, as desired, for the purpose of increasing or decreasing the speed of v the bicycle while propelling it on a level or up an incline.

On the figures of the drawings like letters refer to like parts.

Figure l is a perspective view of a bicycle with my improvement applied. Fig. 2 is a view, partly in section, of the crank-shaft, sprocket-Wheels, and movable couplers detached from the bicycle. Fig. 3 is a View of Fig. lis a view of the outer face of a sprocket-wheel. Fig. 5 is a perspective view of a coupler, and Fig. 6 shows the crank-shaft detached.

Referring to the figures, Ais a crank-shaft of the form shown in Fig. 6, having key-seats B B.

C C are couplers having grooves S S, keyseats D D, keys L L, fixed in the seats, and projections E E on the faces, as illustrated in Fig. 5.

F F are sprocket-wheels on the axle of the rear wheel, one of said wheels being of greater diameter that the other.

F F are sprocket-wheels mounted on the crank-shaft. G G in its face and a key-seat Dto receive a key L, which latter is approximately one-half the length of the seat B in the shaft.

H is a shifter pivoted at K to the frame.

I I are armsprojecting from the lower end of the shifter, said arms having attached thereunto clutch-yokes J J, which engage the grooves S S in the couplingsor couplers.

W is a notched bar on the frame, adapted to be engaged by the long arm P of the shifter, and M M are sprocket-chains, of usual con- Each wheel F has depressions struction, for transmitting motion from the crank sprocket-wheels to the sprocket-wheels on the rear-wheel shaft.

It will be observed that the crank-shaft A is supported at its middle portion only in a bearing located at the lower end of the mast and that the sprocket-wheels F F and the clutch mechanisms are on the ends of the crank-shaft. The arms of the shifter carrying the yokes thus necessarily extend to the left and right of the mast, so that the forks may engage the couplers on each side of the shaft-bearing.

The operation of the device is obvious. When the lever-arm P is caused to engage the notch at the left on the bar inA Fig. l, the coupler C at the right-hand end of the crankshaft is brought into engagement with the sprocket-Wheel F, the key L sliding into the seat Dand the projections E E meshing with the depressions G G. The coupler at the left is simultaneously thrown out of engagement with the sprocket-Wheel on the left end of the pedal-shaft. The sprocket-wheels on the shaft of the rear wheel being of different diameters, the speed of the bicycle will depend upon the position occupied by the shifter. It is clear that in some instances the sprocketwheels on the shaft'of the rear wheel may be of the same diameter and those on the pedalshaft of different diameters.

What I claim is'-n l. The combination inabicycle-propelling mechanism, constructed and operating substantially as described, of sprocket-wheels, F F; sprocket-Wheels, F F; shaft, A, having seats, B B; couplers, C C, having projections, E E, and keys, LV L; chains, M M; and a shifter; the said Wheels, F F, having key-seats and depressions adapted to mesh with the keys and projections on the couplers, C C, and each seat, B, being` substantially twice the. length of a key, L; in substance as set with two sprocket-wheels thereon; a cranki shaft having two sprocket-wheels thereon; chains, M M, for transmitting motion from the front to the rear sprocket-Wheels; independent couplers, C C, having keys, L L, movable in the seats, B B, made in said shaft, long enough to always afford engagement with said keys, and adapted to also engage alternately the seats, D D', in the sprockets, and also having grooves, S S; and a shifter,

H, provided Withclntoh-yokes loosely engaging the grooves, S S, inthe couplers; substantially as and for the purposes set forth. 1o

JOHN J. HENTZ. Witnesses:

JOHN H. GUNDERsDoRF, CHAS. O. HALL. 

